Time Spent Walking and Risk of Diabetes in Japanese Adults: The Japan Public Health Center-Based Prospective Diabetes Study

Association between serum ALT levels and incidence of new-onset diabetes in general population of Japanese: a longitudinal observational study (ISSA-CKD)

OBJECTIVE

We aimed to clarify the relationship between serum alanine transaminase (ALT) levels and incidence of new-onset diabetes in a Japanese general population.

SETTING

Population-based retrospective cohort study using annual health check-up data for residents of Iki City, Nagasaki Prefecture, Japan.

PARTICIPANTS

A total of 5330 Japanese individuals (≥30 years old) without diabetes at baseline were analysed.

PRIMARY AND SECONDARY OUTCOME MEASURES

Serum ALT levels were determined using an enzymatic method and were classified into gender-specific quartile groups as follows: group 1 (3-16 U/L in men and 3-13 U/L in women), group 2 (17-21 U/L in men and 14-16 U/L in women), group 3 (22-29 U/L in men and 17-22 U/L in women) and group 4 (30-428 U/L in men and 23-268 U/L in women). The study outcome was the incidence of diabetes (fasting glucose ≥7.0 mmol/L, non-fasting glucose ≥11.1 mmol/L, glycated haemoglobin ≥6.5% or use of glucose-lowering therapies).

RESULTS

After an average follow-up period of 5.0 years, 279 individuals developed diabetes. The incidence rate of diabetes increased with elevation of serum ALT levels (0.7% per 100 person-years in group 1, 0.9% in group 2, 0.9% in group 3 and 1.7% in group 4) (p<0.001 for trend). This association was significant after adjustment for other risk factors including age, sex, obesity, hypertension, dyslipidaemia, smoking, current daily alcohol intake and regular exercise (p<0.001 for trend). Comparable associations were observed between men and women (p=0.459 for interaction).

CONCLUSION

Serum ALT levels were associated with future development of diabetes in the general Japanese population.

Eating Speed and Incidence of Diabetes in a Japanese General Population: ISSA-CKD

Background: We investigated whether eating speed was associated with the incidence of diabetes in a Japanese general population. Methods: A total of 4853 Japanese individuals without diabetes at baseline were analyzed. Self-reported eating speed was categorized as slow, medium, and fast on the basis of questionnaire responses. The study outcome was the incidence of diabetes. Results: After an average follow-up period of 5.1 years, 234 individuals developed diabetes. The incidence of diabetes per 1000 person-years was 4.9 in the slow eating speed group, 8.8 in the medium eating speed group, and 12.5 in the fast eating speed group, respectively (*** p < 0.001 for trend). The HRs were 1.69 (95%CI 0.94–3.06) for the medium eating speed and 2.08 (95%CI 1.13–3.84) for the fast eating speed, compared to the slow eating speed (* p = 0.014 for trend) after adjustment for age, gender, smoking status, drinking, exercise, obesity, hypertension, and dyslipidemia. Conclusion: Faster eating speed increased a risk for the incidence of diabetes in a general Japanese population.

Elevated alanine aminotransferase and low aspartate aminotransferase/alanine aminotransferase ratio are associated with chronic kidney disease among middle-aged women: a cross-sectional study

BACKGROUND

Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) to ALT ratio (AST/ALT ratio) have been shown to be related to non-alcoholic fatty liver disease or insulin resistance, which was associated with chronic kidney disease (CKD). However, it is unclear whether ALT and AST/ALT ratio are associated with CKD. In this study, we examined the relationship of ALT and AST/ALT ratio to CKD among middle-aged females in Japan.

METHODS

The present study included 29,133 women aged 40 to 64 years who had an annual health checkup in Japan during April 2013 to March 2014. Venous blood samples were collected to measure ALT, AST, gamma-glutamyltransferase (GGT), and creatinine levels. In accordance with previous studies, ALT > 40 U/L and GGT > 50 U/L were determined as elevated, AST/ALT ratio < 1 was regarded as low, and CKD was defined as estimated glomerular filtration rate < 60 mL/min/1.73 m² and/or proteinuria. Logistic regression model was used to calculate the odds ratio (OR) and 95% confidence interval (CI) for CKD.

RESULTS

"Elevated ALT and elevated GGT" and "elevated ALT and non-elevated GGT" significantly increased the OR for CKD when compared with "non-elevated ALT and non-elevated GGT" (OR: 2.56, 95% CI: 2.10-3.12 and OR: 2.24, 95% CI: 1.81-2.77). Compared with "AST/ALT ratio ≥ 1 and non-elevated GGT", "AST/ALT ratio < 1 and elevated GGT" and "AST/ALT ratio < 1 and non-elevated GGT" significantly increased the OR for CKD (OR: 2.73, 95% CI: 2.36-3.15 and OR: 1.68, 95% CI: 1.52-1.87). These findings still remained after adjustment for confounders.

CONCLUSIONS

Elevated ALT was associated with CKD regardless of GGT elevation. Moreover, low AST/ALT ratio was also associated with CKD independent of GGT elevation.

Combined aerobic and resistance training, and incidence of diabetes: A retrospective cohort study in Japanese older women

AIMS/INTRODUCTION

To investigate the relationship between combined aerobic and resistance training, and the incidence of type 2 diabetes mellitus.

MATERIALS AND METHODS

The present study included 10,680 Japanese women. Participants enrolled between 2005 and 2010, and were followed up until 2014. The frequency of combined training was counted for the first 3 months, the 6th month and the 9th month. In 2014, women reported whether or not they had diabetes, as well as the year of developing diabetes. Hazard ratios and 95% confidence intervals (CI) for the incidence of type 2 diabetes were obtained using Cox proportional hazard models.

RESULTS

The median duration of follow up was 5 years, with 166 women developing type 2 diabetes. Using the lowest frequency of training group (1st quartile) as the reference, the hazard ratios for the second through fourth quartiles was as follows: 0.95 (95% CI 0.64-1.41), 0.73 (95% CI 0.48-1.13) and 0.69 (95% CI 0.44-1.07), respectively (P for trend = 0.116). After adjustment for age, body mass index and thigh circumference, the hazard ratios were: 0.84 (95% CI 0.56-1.26), 0.69 (95% CI 0.45-1.06) and 0.61 (95% CI 0.39-0.95), respectively (P for trend = 0.040).

CONCLUSIONS

A higher frequency of combined aerobic and resistance training is associated with a lower risk of developing type 2 diabetes in Japanese women.

Television viewing time, walking time, and risk of type 2 diabetes in Japanese men and women: The Japan Collaborative Cohort Study

We examined the effect of television viewing and walking on the risk of type 2 diabetes among an Asian population. A total of 25,240 participants (9786 men and 15,454 women) aged 40-79 years, with no history of diabetes, stroke, coronary heart disease, or cancer at the baseline (1988-1990) and who have completed the 5-year follow-up questionnaire were included. During the 5-year follow-up, 778 new cases of type 2 diabetes were reported (397 men and 381 women). Television viewing time was positively associated with risk of type 2 diabetes (p for trend = 0.01). The multivariable OR (95% CI) for ≥5 h/day versus <2 h/day television viewing was 1.51 (1.03-2.19) in women and 1.06 (0.71-1.59) in men (p for interaction = 0.82). Walking time was inversely associated with type 2 diabetes risk in a fully adjusted model (p for trend = 0.02). The multivariable OR for type 2 diabetes of ≥1 h/day walking time was 0.87 (0.71-1.06) compared with 0.5 h/day walking time. The inverse association was found in men (p for trend = 0.02), but not in women (p for trend = 0.38) (p for interaction = 0.36). The multivariable OR for type 2 diabetes of <5 h/day television viewing and ≥1 h/day walking times was 0.72 (0.55-0.94) in fully adjusted model compared with ≥5 h/day television viewing and <1 h/day walking times. Limiting television viewing time and increasing walking time may reduce risk of type 2 diabetes among Japanese.

Is a hilly neighborhood environment associated with diabetes mellitus among older people? Results from the JAGES 2010 study

BACKGROUND

Although living in a hilly environment may promote muscular activity in the daily lives of residents, and such activity may prevent diabetes mellitus, few studies have focused on the impact of living in a hilly environment on diabetes mellitus. The purpose of this study was to investigate the impact of a hilly neighborhood environment on DM in older people.

METHODS

We used data from the Japan Gerontological Evaluation Study, a population-based, cross-sectional study of individuals aged 65 or older without long-term care needs in Japan, which was conducted in 2010. A total of 8904 participants in 46 neighborhoods had responded to the questionnaire and undergone a health check. Diabetes mellitus was diagnosed as HbA_1c ≥ 6.5% and those undergoing treatment for diabetes mellitus. Poorly controlled diabetes mellitus was diagnosed in those without other chronic diseases who had an HbA_1c > 7.5%, and in those with other chronic diseases if their HbA_1c was >8.0%. Neighborhood environment was evaluated based on the percentage of positive responses in the questionnaire and geographical information system data. A multilevel analysis was performed, adjusted for individual-level risk factors. Furthermore, sensitivity analysis was conducted for those who were undergoing treatment for diabetes mellitus (n = 1007).

RESULTS

After adjustment for other physical environmental and individual covariates, a 1 interquartile range increase (1.48°) in slope in the neighborhood decreased the risk of poorly controlled diabetes mellitus by 18% (odds ratio [OR]: 0.82, 95% confidence interval [CI]: 0.70-0.97). Sensitivity analysis confirmed that larger slopes in the neighborhood showed a significant protective effect against diabetes mellitus among those who were undergoing treatment for diabetes mellitus (OR: 0.73, 95% CI: 0.59-0.90).

CONCLUSION

A hilly neighborhood environment was not associated with diabetes mellitus, but was protective against poorly controlled diabetes mellitus.